Tractor plane



March 16, 1943. c, GIENGER I r 2,313,934

TRACTOR PLANE Filed-May 6, 1940 2 Sheets-Sheet 1 WWWWW 5S March 16, 1943. A.-c. GIENGER TRACTOR i'LAuE Filed May 6, 1940 2 Sheets-Sheei 2 INVENTQR ATTO R N EYS WITNESS Patented Mar. 1a, 1943 UNITED ST My invention relates to new and useful improvements in aircraft construction.

An important object of my invention is to provide an aircraft construction embodying a power unit that is unique in its association with the body of the airplane, the propeller and drive means of the power unit being arranged in wind tunnels at opposite sides of the body to draw a current of air through the forward end of the tunnel and todischarge the same through the rearward end thereof in a manner to develop a substantial tractive power or force sufiicient to propel the craft forward in flight.

Another object of my invention is to provide an aircraft construction of the above-mentioned character wherein the rearward end of the tunnels will direct the curren t'of air against the tail assembly of the airplane in a manner to improve the response of the plane to the controls.

Other objects and advantages of my invention, will be apparent during the course of the following description.

In the drawings, forming a part of this specification, and wherein like numerals are employed to designate like parts throughout the same,

Figure 1 is a front elevation of an airplane constructed in accordance with my invention,

Figure 2 is a vertical sectional view taken on the line 2-2 of Figure 1,

Figure 3 is a vertical sectional view taken on the line 33 of Figure 2, and

Figure 4 is an enlarged longitudinal sectional View of one of the wind tunnels and power unit embodying a part of my invention.

In the accompanying drawings, wherein for the purpose of illustration, is shown a preferred embodiment of my invention, the numeral l designates an airplane in its entirety. The airplane includes a body I i, of standard shape and construction, which body is supported by the landing gear I2 and supports the transverse wing 13.

The wind tunnels I4 are arranged at opposite sides of the body and below the wing I 3, said wind tunnels being identical in their construction and comprising cylindrical housings l 5 preferably having a diameter substantially. equal to the height of the body, whereby the tunnels may be made to join smoothly and evenly therewith, as illustrated in Figure 1. The inner walls of the tunnels have a constant diameter throughout their length and the walls are continuous or unbroken by openings or recesses of any nature.

A power unit of identical construction and operation is arranged within each of the tunnels. A detailed description of one of the units will, therefore, suffice. The propeller l6 is'coaxially mounted for rotation adjacent the forward end of the tunnel. The hub portion ll of the propeller comprises a hollow drum the middle portion it of which is of cylindrical formation having a diameter substantially one-half the diameter of the wind tunnel in which it is mounted, and the opposite ends l9 and 20 of the middle portion are longitudinally tapered, as clearly illustrated in Figure 4. The diametrically opposed right angularly disposed propeller blades 34. are secured to and extend radially from the middle portion of the hub I8. Each of the blades is transversely bowed and arcuately curved in a manner to generate a current of air toward the rearward end of the tunnel; the terminal ends of the blades being arranged in close proximity with the inner wall of the tunnel.

A shaft 2! extends axially through the propeller drum and the extending ends 26 and 2! thereof are fixedly secured to the tapered ends of the drum by the set screws 22. The end portions of the shaft extending longitudinally from the opposite ends of the drum comprise stub shafts or shanks adapted to be journaled in the longitudinally spaced supports 23 and 24. The support 23 comprises a spider secured in the forward end of the tunnel by the set screws 25; the forward end 26 of the shaft being supported within the central recess 28 by the roller bearing 29 to promote a substantially frictionless rotation of the propeller therein. The rearward end Zl of the shaft is received by the gear housing so and has the gear 3! fixedly secured thereto and in meshed relation with the gear train 32. The gears within the housing are driven by an internal combustion engine 33 arranged within the tunnel rearwardly of the propeller.

The chambers or tanks 35, defined by the juncture of the wind tunnels With the substantially rectangular body of the plane, may be conveniently used as gas reservoirs. As clearly illustrated in Figure 3, the tanks are disposed above the internal combustion engine to permit a gravity feed therefrom through the conduit 35 to the carburetor 37 of the engines.

The exhaust gases from the engines may be introduced into the hollow wing structure l3 to heat the same and prevent the formation of ice on the outer surfaces thereof. I have, therefore, provided conduits 38 extending between the intake manifolds 39 of the engines and the intericr of the wing adjacent the forward edge thereof. The upper end 40 of the conduits discharge toward the forward end of the win whereby the exhaust gases will be required to circulate through the entire wing structure, as illustrated by the arrows in Figure 2. A plurality of discharge ports 4| are provided adjacent the rearward or trailing edge of the Wing to permit the exhaust gases to exit therefrom.

The ratio of the gears in the gear housings 30 should be such that a relatively slow actuation of the engine 33 will be sufiicient to impart a substantially rapid rotation to the propeller IS. The rapid rotation of the propellers will cause a current of air to be drawn through the forward end of the tunnel and discharged from the rearward end thereof and against the tail assembly of the plane. the current of air is forced directly and uninterruptedly from the rearward end of the tunnel and against the rudders and elevators of the tail assembly will assure a proper response of the plane to the controls. The greatest pressure developed by fan blades will be at the outer ends of the fan blades and the air will, therefore, move toward the center of the tunnel. The large size of the drum and the longitudinally tapered rearward end 20 thereof will prevent the formation of eddy currents in the center of the tunnel and will prevent any of the air at the center of the fan from being forced to the front of the tunnel. The combined effect of the drum and fan, rotating in the above described manner in the tunnel, will be to direct all of the air through the rearward end of the The manner in which tunnel to develop a substantial tractive force or power.

It is to be understood that the wind tunnels I4 may be of varying size and length in accordance with the particular construction of the aircraft to which it is to be applied and that two or more fans may be employed in each of the tunnels if desired. The form of my invention, herewith shown and described, is to be taken as a preferred example of the same. Various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of my invention, or scope of the ap pended claim.

Having thus described my invention, I claim:

A wind tunnel for aircrafts, comprising an elongated cylinder of the same diameter throughout its length, a bearing supported centrally within the outer end of the cylinder by radially extending spokes, a transmission housing supported within the cylinder and spaced some distance from the bearing, a bearing carried by the transmission housing in alinement with the first mentioned bearing, a shaft mounted in said bearing and having a gear connection with the transmission, a drum mounted on the shaft and having elongated curved blades a motor support carried by the cylinder in beyond the transmission housing, a motor carried thereby and having its shaft in a horizontal alinement with the fan shaft and carrying a gear driving the transmission.

ALBERT C. GIENGER. 

